Replacement of Trevi Boost with a Trevi Therm

[pooksahib]

Hi all. I've had a 'granny flat' added to my bungalow. My builder, who does his own plumbing, recommended and installed a Trevi Boost shower (it uses the Venturi principle whereby cold pressure 'draws through' the hot water with no need for a pump). Unfortunately, the shower temperature is woeful and the Trevi people have now told my builder that it won't work due to the way he's connected the hot feed.

What he's done is taken the new hot pipe from the top of the hot water cylinder up into the loft, along 7 metres then down to the new shower. (It was not possible to put the new pipes under the floorboards.)

So now my builder/plumber is suggesting a Trevi Therm shower coupled with a pump. I've had a look at the instructions for the Therm (easily obtainable online) and am a bit concerned by what I saw on page 2 - four suggested ways of connecting the hot feed ranging from Most Preferred to Least Preferred. What worries me is that even the Least Preferred way had the new pipe coming down to the floor, not up to the roof!

But bear in mind that I'm to get a pump installed as well (up in the loft). Can anyone foresee any problems with the proposed new shower? My thanks in advance for all responses.

 

[bathstyle]

Where is he proposing to fit the pump, in the loft?

How far is the bottom of the cold storage cistern from the top of your ceiling joists?

I assume from your description that it's a stuart turner pump.

Take a look at the literature again, they suggest an Essex flange is better than a Surrey flange, in my experiance both will work well, although an Essewx is compulsary when fitting the 4 bar models I believe.

The important thiong is is to provide an air free supply to your shower pump.

 

[pooksahib]

Hi bathstyle. Yes, pump in loft. I'll see if he knows yet what type it's to be and report back. The cold tank sits just a plank's width above the joists.

PS Just spoken to my builder. He's spoken to Trevi and the upshot is there could be a problem with air intake as the pump would be too close to the vent pipe from the hot cylinder. So now he's talking about replacing the hot cylinder with a pressurised one. Any views on that?

I'd wish to leave the existing cylinder if at all possible.